Methylation and Demethylation of Dimethylarsinic Acid in Rats Following Chronic Oral Exposure

Metabolites of dimethylarsinic acid (DMA) were studied in rats chronically exposed to DMA in drinking water. The urine was collected by forced urination at the end of 8, 20 and 30 weeks and the feces at the end of 30 weeks. The samples were analyzed for arsenic species by a combined system of ion chromatography and inductively coupled plasma mass spectrometry (IC–ICP–MS). Increases in arsenite, DMA, trimethylarsine oxide and a still-to-be-identified arsenic compound (which was eluted immediately after monomethylarsonic acid on the chromatogram) were detected in both urine and feces. At the 100 mg l⁻¹ dose, DMA was the main component in the urine; arsenite was a main component in the feces. The results indicate that, besides undergoing methylation, DMA can be demethylated to inorganic arsenic, and demethylation of DMA may be associated with intestinal bacteria     

Speciation of Arsenic in Rice by Ion Chromatography with Online Anion Suppression and Inductively Coupled Plasma Mass Spectrometry

Arsenic speciation in rice has received attention due to its impact on food safety and human health. In this study, a sensitive method was developed for the determination of inorganic arsenic in rice using online anion suppression with ion chromatography and inductively coupled plasma mass spectrometry. HCl of 0.01?mol/L was the optimal extracting agent, and 38?mmol/L sodium carbonate and 15?mmol/L sodium acetate were used as the mobile phase to separate dimethylarsinic acid (DMA), arsenite, monomethylarsonic acid (MMA), and arsenate. The results showed that there were no significant losses or transformations with the anion suppressor and an improvement in sensitivity. The limits of quantification were 0.1?µg/L for DMA, As(III) and MMA, and 0.2?µg/L for As(V). The procedure was used to determine inorganic arsenic in rice; As(III) and DMA were the primary forms present. The reproducibility from seven measurements showed that the relative standard deviation was less than 1.68%. The recoveries were from 99.76 to 110.42%. The present work offers a new approach for the determination of inorganic arsenic in rice.     

Imaging of metals in biological tissue by laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS): state of the art and future developments

Laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) is well established as a sensitive trace and ultratrace analytical technique with multielement capability for bioimaging of metals and studying metallomics in biological and medical tissue. Metals and metalloproteins play a key role in the metabolism and formation of metal‐containing deposits in the brain but also in the liver. In various diseases, analysis of metals and metalloproteins is essential for understanding the underlying cellular processes. LA–ICP–MS imaging (LA–ICP–MSI) combined with other complementary imaging techniques is a sophisticated tool for investigating the regional and cellular distribution of metals and related metal‐containing biomolecules. On the basis of successful routine techniques for the elemental bioimaging of cryosections by LA–ICP–MSI with a spatial resolution between 200 and ~10 µm, the further development used online laser microdissection ICP–MSI to study the metal distribution in small biological sample sections (at the cellular level from 10 µm to the submicrometer range). The use of mass spectrometric imaging of metals and also nonmetals is demonstrated on a series of biological specimens. This article discusses the state of the art of bioimaging of metals in thin biological tissue sections by LA–ICP–MSI with spatial resolution at the micrometer scale, future developments and prospects for quantitative imaging techniques of metals in the nanometer range. In addition, combining quantitative elemental imaging by LA/laser microdissection–ICP–MSI with biomolecular imaging by matrix‐assisted laser desorption/ionization–MSI will be challenging for future life science research. Copyright © 2013 John Wiley & Sons, Ltd.     

基于巯基功能化磁球的磁固相萃取-ICP-MS联用用于环境水样中无机砷形态分析

该文制备了一种可在pH 5.0~9.0范围内选择性吸附As(Ⅲ)的巯基（—SH）修饰的环氧基改性磁性纳米材料（Fe3O4@SiO2@GMA—S—SH MNPs）,将其与新型MSPE-ICP-MS联用实现了水中As(Ⅲ)和As(Ⅴ)的分离分析,As(Ⅴ)经Na2S2O3/KI还原后,采用MSPE-ICP-MS测得总砷含量,然后通过差减法计算。结果显示,方法对As(Ⅲ)的检出限（LOD）为1.5 ng·L-1,富集倍数为150倍,线性范围为5~3 000 ng·L-1,相对标准偏差（RSD）（c=10 ng·L-1,n=7）为9.6%。将该方法用于水质标准样品（GSB07-3171-2014）中无机砷形态分析,测定结果与参考值一致。采用该方法测定自来水As(Ⅲ)和As(Ⅴ)的含量分别为0.036、0.043 μg·L-1,湖水中含量分别为0.24、0.43 μg·L-1,加标回收率为80.9%~101%,RSD为1.5%~10%。该方法具有检出限低、富集倍数大、吸附/解吸动力学快、抗干扰能力强等优点,可用于实际水样中无机砷的形态分析。     

Arsenic speciation in some environmental samples: a comparative study of HG–GC–QFAAS and HPLC–ICP–MS methods

Some water and soil extracts polluted with arsenic, and a sewage sludge certified for total arsenic have been analysed by high‐performance liquid chromatography–inductively coupled plasma–mass spectrometry (HPLC–ICP–MS) and hydride generation–gas chromatography– quartz furnace atomic absorption spectrometry (HG–GC–QFAAS techniques.) Detection limits in the range of 200–400 and 2–10 ng l⁻¹ respectively allowed the determination of inorganic [As(III), As(V)] and methylated (DMA, MMA, TMAO) arsenic species present in these samples. Results obtained by both methods are well correlated overall, whatever the arsenic chemical form and concentration range (8–10 000 μg l⁻¹). Comparison of these results enabled us to point out features and disadvantages of each analytical method and to reach a conclusion that they are suitable for arsenic speciation in these environmental matrices. Copyright © 2000 John Wiley & Sons, Ltd.     

Quantitative Speciation of Arsenic in Water and Sediment Samples from the Mokolo River in Limpopo Province,South Africa

The Mokolo River is disposed to environmental contaminants such as arsenic (As) due to its proximity to several anthropogenic activities. Speciation of As in water and sediment samples from Mokolo River is crucial to evaluate the level and distribution of As in the river and underlying sediment since toxicity depends on its chemical forms. In this study, As species in water and sediment were determined by developing a new method for sediment extraction. Effective microwave-assisted extraction of As species in sediment samples was achieved using 0.3?M (NH₄)₂HPO₄ and 50?mM EDTA, which showed no species interconversion during extraction. The chromatographic separation and detection of As(III), dimethylarsinic acid (DMA), monomethylarsonic acid, and As(V) in water and sediment samples were achieved by coupling to high-performance liquid chromatography to inductively coupled plasma mass spectrometry. Baseline separation of four As species was achieved in 12?min using gradient elution with 10 and 60?mM NH₄NO₃ at pH 8.7 as the mobile phase. The analytical figures of merit and validation of analytical procedures were assessed and adequate performance and percentage recoveries ranging from 81.1 to 102% for water samples and 73.0–92.0% for sediments were achieved. The As species concentration in water and sediment samples was found to be in the range of 0.304–4.99?µg?L^?1 and 74.0–92.0?ng?g^?1, respectively. DMA was not detected in both water and sediment samples.     

HPLC-ICP-MS在食品中硒和砷形态分析及其生物有效性研究中的应用

食品中含有与人体健康密切相关的多种微量元素,微量元素的毒性和生物有效性取决于它们的化学形态。食品中的微量元素形态分析及其生物有效性研究对食品安全控制与营养评价具有至关重要的意义。本文扼要介绍了高效液相色谱与电感耦合等离子质谱（HPLC-ICP-MS）联用情况,该技术以不同的色谱分离柱完成各种分析物的分离,具有高灵敏度、高选择性、线性范围宽、检测限低、多元素同时检测等特点,在微量元素形态分析中占有重要的地位。综述了HPLC-ICP-MS在食品微量元素形态分析及其生物有效性研究中的应用,重点介绍了富硒酵母、蒜类植物、富硒营养保健品等食品中硒形态和海产品、农产品等食品中砷形态的研究,以及其它多种微量元素的形态分析和这些微量元素在生物体内的代谢。     

微波酸提取/液相色谱-电感耦合等离子体质谱法测定动物源性中药中6种砷形态

建立了微波酸提取/液相色谱-电感耦合等离子体质谱联用(LC-ICP-MS)测定动物源性中药中6种砷形态(亚砷酸盐As(Ⅲ),砷酸盐As(V),一甲基砷MMA,二甲基砷DMA,砷甜菜碱As B和砷胆碱As C)的分析方法。采用1%HNO_3溶液在80℃微波提取10 min,经离心分层,过固相萃取SEP C18柱和0.45μm滤膜,以25 mmol/L NH_4H_2PO_4溶液(p H 6.7)-乙醇(99∶1,体积比)为流动相进行等度洗脱,各砷形态在10 min内实现基线分离。结果显示,6种砷形态在1.0~100.0μg/L范围内线性关系良好,相关系数为0.999 5~0.999 7,方法检出限(LOD)为0.24~1.0μg/kg,相对标准偏差(RSD)为0.96%~2.0%。将方法应用于地龙、水蛭、海螵蛸、桑螵蛸、石决明和鸡内金中6种砷形态的测定,加标回收率为94.2%~103.8%,提取效率为95.5%~102.8%,优于热提取法。方法快速、准确、重现性好,适用于动物源性中药及类似样品中的砷元素形态分析及质量监控。     

毛细管电泳-电感耦合等离子体质谱法测定藻类中6种不同形态的砷化合物

建立了一种利用毛细管电泳与电感耦合等离子体质谱联用技术(CE-ICP-MS)分析检测6种不同形态砷化合物的方法。详细研究了缓冲溶液的种类、pH值和浓度,分离电压以及进样时间等因素对6种砷化合物的分离度、灵敏度和重现性等的影响。结果表明,在最佳条件下,三价砷(As3+)、一甲基砷(MMA)、二甲基砷(DMA)、五价砷(As5+)、砷胆碱(AsC)和砷甜菜碱(AsB)6种化合物在25 min内得到完全分离。6次平行测定中,6种砷化合物峰面积的相对标准偏差(RSD)为3%～5%,检出限(以As计)(3倍信噪比)为0.08～0.12 μg/L。应用该方法成功地对海带中6种砷化合物进行了分析,回收率为90%～103%。该方法具有耗时短、灵敏度高、样品消耗量少、稳定性好等优点,可用于藻类样品中不同形态砷化合物的分析。     

Determination of Cisplatin and Carboplatin Anticancer Drugs by Non-suppressed Ion Chromatography with an Inductively Coupled Plasma Atomic Emission Detector

Two non-suppressed ion chromatographic (IC) methods, one with an anion and one with a cation separation column, were investigated for first time to determine cisplatin and carboplatin anticancer drugs using inductively coupled plasma–atomic emission spectrometry as a detector. The Shodex IC YK-421 (4.6?×?125?mm²) column was considered as the preferred separation column. The mobile phase in this case consisted of tartaric acid and boric acid. The flow rate was 1?mL/min and the injection volume was 20 μL. Separation was carried out in about 2?min with column temperature at 30°C after optimization. With cationic separation, the cisplatin elutes first, as opposed to the anionic one, where it elutes second. In addition, with both columns, a second peak for cisplatin appears which is attributed to a hydrolysis product of the drug. For the cation chromatographic method, the repeatability ranged from 3.1 to 5.9%, whereas the inter-day precision was 13.3 and 16.3% for cisplatin and carboplatin, respectively. The detection limits were 0.1?mg/?L Pt for both compounds. The proposed method was applied to the analysis of human urine with satisfactory recoveries indicating that there are no matrix effects.     

离子色谱-电感耦合等离子体质谱联用法测定水中痕量BrO-3及Br-

建立了离子色谱-电感耦合等离子体质谱联用技术(IC-ICP-MS)用于饮用水中的痕量BrO-3及Br-的测量.使用DIONEX Carbopac PA-100(4 mm×250 mm i.d.)在流速1 mL/min及5 mmol/L NH4NO3(pH 5.7)淋洗液下进行BrO-3和Br-的分离.该方法以100 μL进样量对BrO-3的检出限为0.0027 μmol/L(0.22 μg/L);对Br-的检出限为0.0067 μmol/L (0.54 μg/L).对水样的分析结果表明,所测矿泉水中的BrO-3浓度大大超出了世界卫生组织最新<饮用水水质准则>中所规定的溴酸盐的指导值,而所测量的青岛崂山区生活用水则未检出BrO-3.     

Seasonal changes in arsenic speciation in Fucus species

Arsenic speciation in a brown alga, Fucus gardneri, collected in Vancouver, B.C., Canada, was carried out by using high-performance liquid chromatography–inductively coupled plasma–mass spectrometry (HPLC–ICP–MS). Hydride generation–atomic absorption spectrometry (HG–AAS) was used for total arsenic determination. The relative amounts of some arsenosugars 1 in growing tips are found to be different in comparison with the remainder of the plant. Fucus samples collected in summer contain 9 ppm of total arsenic. Most of the arsenic species are extractable. Fucus samples collected in winter contain relatively higher amounts of arsenic, 16–22 ppm, but only low amounts of this are extractable. © 1998 John Wiley & Sons, Ltd.     

Speciation of Volatile Selenium Species in Plants Using Gas Chromatography/Inductively Coupled Plasma Mass Spectrometry

 Gas chromatography/inductively coupled plasma mass spectrometry (GC/ICP MS) coupled with solid phase micro extraction can provide a simple, extremely selective and sensitive technique for the analysis of volatile sulfur and selenium compounds in the hea     

Investigation of metal-binding metallothioneins in the tissues of rats after oral intake of cinnabar

The multi-metal-binding MT fractions in rat tissues after oral intake of cinnabar were characterized by hyphenated size-exclusion chromatography (SEC) and inductively coupled plasma mass spectrometry (ICP–MS). With the increase of both the feeding time and dosage of cinnabar the amounts of Hg-binding MT fractions in rat kidney of groups fed cinnabar increased significantly compared with the control group. Meanwhile, more Cu-binding MT were synthesized in the rat kidney, which confirmed the manipulating effect of MT in the homeostasis of Cu for detoxification of nephritic mercury. Although the Hg-binding MT fractions in rat liver of all cinnabar groups were almost independent of cinnabar dosage (2.5–5.0 g kg^–1 bw) and feeding time (2–4 weeks), the amount was much higher than that of the control group. The amounts of Hg-MT in other rat tissues of the cinnabar groups and the control group were compared and their significance is discussed.     

气相色谱/电感耦合等离子体质谱测定植物中挥发性硒化合物

Severalinstrumentalmethodscanbeusedforthedetectionanddeterminationofvolatileselenium(Se)andsulfur (S)compounds .Theserelyprimari lyongaschromatography (GC)forseparationanddifferentdetectiontechniques ,includingatomice missiondetection (AED ) ,massspectrom…     

Evaluation of Manganese(II) and Manganese(VII) Speciation in Water Samples by Ion Pair High-performance Liquid Chromatography-inductively Coupled Plasma Mass Spectrometry

The speciation of Mn(II) and Mn(VII) is reported by ion pair chromatography. To optimize the separation, sample pH, ion pair reagent, Mn(II) complexing agent, and composition of mobile phase were characterized. The separation of Mn(II) and Mn(VII) was performed using ethylenediamine tetraacetic acid to complex Mn(II), tetrabutylammonium hydroxide as an ion pair reagent, and a C8 column. The separation of the manganese species was demonstrated by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC ICP-MS). The conversion of Mn(VII) to Mn(II) occurred during the separation and influenced the quantification; hence, the factors affecting this process including the storage time, manganese species ratio, and sample matrix composition were evaluated and suitable calibration was demonstrated. The method was validated by characterization of the selectivity, specificity, linearity, limits of detection and quantification, repeatability, and intermediate precision. The detection limit for Mn(II) was 0.22 µg?L^?1, while for Mn(VII), the value was 1.55 µg?L^?1.     

The identification of some water-soluble arsenic species in the marine brown algae Fucus distichus

The extraction and clean-up procedures developed to isolate the water-soluble arsenic species present in the marine macroalga Fucus distichus, from British Columbia, Canada, are described. The arsenic species were extracted into methanol and then subjected to gel-permeation and ion-exchange chromatography. Fractions high in arsenic were identified by using graphite furnace atomic absorption spectroscopy (GF-AAS), and further investigated by using high-performance liquid chromatography coupled to inductively coupled plasma–mass spectrometry (HPLC–ICP MS). By using different HPLC columns and mobile-phase conditions, the four major arsenic-containing compounds present in the macroalga were positively identified as arsenosugars; one minor compound remained unidentified. © 1997 John Wiley & Sons, Ltd.     

Enhanced HPLC‐MS/MS method for the quantitative determination of the co‐administered drugs ceftriaxone sodium and lidocaine hydrochloride in human plasma following an intramuscular injection and application to a pharmacokinetic study

A sensitive HPLC–MS/MS method was established for the quantification of ceftriaxone sodium (CFT) and lidocaine HCl (LDC) in human plasma utilizing cefixime (CFX) and tadalafil (TDA) as internal standards. The analytes were extracted from human plasma by protein precipitation using acetonitrile. Chromatographic separation was performed on Kinetex C₁₈ (50.0 × 4.6 mm, 5 μm particle size) column with methanol–0.01 M ammonium acetate pH 6.4 (70: 30, v/v) as mobile phase. Multiple reaction monitoring involving the transitions 555.10 → 396.20, 235.20 → 86.00, 454.20 → 284.80 and 390.20 → 268.20 was utilized to quantify CFT, LDC, CFX and TDA, respectively, using a triple quadrupole mass spectrometer which was operated in positive ion mode. The method revealed linearity in the concentration range of 3.0–300.0 μg/mL for CFT and 3.0–300.0 ng/mL for LDC. The validation of the method was achieved in accordance to the US Food and Drug Administration guidelines. A pharmacokinetic study was performed on healthy Egyptian volunteers after intramuscular injection of sterile ceftriaxone sodium (1 g CFT dissolved in 3.5 mL of 1% LDC) after approval from the ethics committee. The pharmacokinetic parameters were: C_max 141.15 ± 39.84 (μg/mL) and 55.02 ± 9.36 (ng/mL); t_max (h) 2.50 ± 0.50 and 1.5 ± 0.50; t_½ (h) 7.30 ± 2.98 and 4.23 ± 1.96; and K_el (h⁻¹) 0.10 ± 0.04 and 0.20 ± 0.13 for CFT and LDC, respectively.     

Determination of different arsenic species in food‐grade spirulina powder by ion chromatography combined with inductively coupled plasma mass spectrometry

A “two‐step” pressurized microwave‐assisted extraction method coupled with ion chromatography with inductively coupled plasma mass spectrometry for the determination of different arsenic species in spirulina samples was developed. The extraction method used H₂O₂/H₂O (1:5, v/v) as solvent to extract all arsenic species except arsenite, which was extracted by using water as solvent. The extraction method had a satisfactory recovery (>96%) and took a short time (20.0 min). With our method, all arsenic species in spirulina samples were completely separated and determined with recoveries of 84–105% and relative standard deviations of 2–4%. Food‐grade spirulina powder samples from seven provinces (Inner Mongolia, Zhejiang, Fujian, Hainan, Yunnan, Jiangsu, and Guangxi) in China were analyzed using the optimized protocol. Arsenate was detected at the concentration range of 170–394 ng/g in all the spirulina samples. Dimethylarsinic acid was detected at the concentration range of 32–839 ng/g in spirulina from above‐six provinces except Guangxi. Monomethylarsonic acid (67 ± 3 ng/g) was detected only in spirulina from Yunnan province. Arsenite was detected at the concentration range of 28–147 ng/g in spirulina from above five provinces except Hainan and Guangxi. Five unknown organic arsenic species were found in spirulina from above six provinces except Guangxi.     

有机化合物对电感耦合等离子体质谱(ICP-MS)法测定食品中总砷的影响

目的 研究有机化合物对电感耦合等离子体质谱法（ICP-MS）测定食品中总砷的影响,分析总结一般规律,为食品中总砷的准确测定提供理论依据。方法 研究了甲醇和乙醇等14种有机化合物对ICP-MS测定砷的动能歧视模式（KED）信号值和动态反应模式（DRC）信号值的影响,通过分析各有机化合物的电离能、极性和溶解度等性质,推测其在ICP-MS测定体系中对砷响应信号值增敏或者抑制的可能机理。结果 有机化合物对ICP-MS的KED模式测定砷离子As+的信号值有增敏效应,对DRC模式测定氧化砷离子AsO+信号值的影响小于KED模式测定As+的信号值,而且过程也更为复杂。相反,氮氧化物会减弱As+和AsO+的信号值。锗、铟等内标元素原子与砷原子在等离子体中电离行为和灵敏度的差异,使得内标元素校准砷测定信号的漂移受到干扰。结论 推测有机化合物影响ICP-MS测定砷响应信号值的可能机理是：有机化合物和氮氧化物经电离或裂解之后分别生成碳离子或多原子碳离子和氮氧离子或氮氧基团,碳离子或多原子碳离子会与砷原子发生电荷转移反应,增强As+或AsO+的信号值,同时有机化合物也可能会与As+竞争氧气而降低AsO+的信号值,而具有强电负性的氮氧基团可能会与As+和AsO+发生电荷转移反应而减弱其信号值。有机化合物对砷的ICP-MS响应信号值的影响可能是受到有机化合物电离能、溶解度、极性和分子结构等综合因素的结果。